Oh, this is a weirdly specific niche that’s actually got some hidden depth. The 'golden lion' tag usually gets mashed up with Fate/stay night’s Shiki Ryougi, and honestly, most of it is pure power fantasy or crossover crack. But there’s one older story I keep going back to, 'Gilded,' that does something different. It treats the concept not as a straight fusion but as a metaphysical identity crisis—Shiki's 'nothingness' clashing with Gilgamesh's 'everything.' It’s less about flashy fights and more about two beings who perceive reality as utterly incompatible trying to occupy the same space.
It’s abandoned after about eight chapters, but what’s there is genuinely haunting. The prose gets very introspective, almost like a character study disguised as a VS debate. You can find it on some of the older Fate-focused archives, though it takes some digging past all the 'Shiki vs Gilgamesh who wins' forum posts. The author had a knack for making their dialogue feel like two monologues crashing into each other, which is pretty fitting for those characters.